Tuning intermediate adsorption and hydrogenation pathways on oxide-derived copper via boron-induced electronic modulation for efficient electrocatalytic nitrate-to-Ammonia conversion

Electrocatalytic nitrate reduction to ammonia (NH 3 ) involves multiple proton-coupled electron transfer (PCET) steps, yet its efficiency is often hindered by sluggish hydrogenation kinetics and the facile desorption of key intermediates. Here, we incorporate boron (B) dopants into oxide-derived copper (B-OD-Cu), achieving a remarkable NH 3 Faradaic efficiency of 99.04% and a yield rate of 0.2341 mmol h −1 cm −2 at −0.7 V vs. RHE, both surpassing those of pristine OD-Cu (NH 3 FE: 92.56%; NH 3 yield: 0.1934 mmol h −1 cm −2 ). Comprehensive experimental and theoretical analyses reveal that B incorporation tailors the local electronic structure of OD-Cu and forms asymmetric B–O–Cu active configurations with efficient PCET channels. The asymmetric electronic environment concurrently optimizes the adsorption/desorption of H 2 O and N-containing intermediates, promotes *H generation, and accelerates stepwise hydrogenation towards NH 3 formation. These findings uncover a clear structure-reactivity correlation, highlighting boron-induced electronic modulation as a powerful strategy to steer charge transfer and intermediate dynamics, thereby offering general design principles for heterogeneous catalysts involved in multi-electron PCET reactions.